Use these skills: https://us.battle.net/d3/en/calculator/wizard#bmOYSj!gYW!ccZYZa.
That's +30-50% damage right there, when you put a Buriza + Star of Azkaranth with Freeze on your scoundrel to proc Cold Blooded.
Get a Mempo with CC. They're pretty cheap these days, at a 90m entry price. Tal's helm with nice rolls is a slightly cheaper alternative, but with the cost differences as low as they are now, I feel like the Mempo is the better deal.
Ditch the ICs for a pair of Zuni boots for the +8% damage bonus. Look for 190 Int, and either 180+ Vit or 70+ AR. The EHP loss is more than made up for by the Mempo.
Zuni boots come with MS, allowing you to drop the Lacuni's for some crafted bracers. Look for 5+ CC, 280+ Int and either Vit, AR or Armor.
Now you also have 3 Zuni pieces, and you can afford to either switch your Marrow to a Tal's or your Pox to a rare. 3-Zuni is totally viable too, though, so you can stick with that as well. Personal preference.
A single Int roll on Inna's pants is kind of a waste. You can roll 70+ Vit and 70+ Int.
Get 150+ Int on your Witching Hour. Less (or even no) Vit would be OK, with all the EHP buffs the rest of my suggestions get you.
And as always: if you want damage, your weapon is where to look. It doesn't seem too bad compared to some of your other pieces though, so YMMV.